For all those with an interest, it does appear that the wire control to
the heater valve really doesn't have a good end on it and thus, the
valve really doesn't close all the way.  This was causing the core to
get worm enough to throw heat into the van.  When I am driving on the
highway in California and the temperature is 100 outside, I didn't need
any more heat.  Had to drop the tire and move the valve to the closed
position to actually get it to shut off (the dash lever didn't go far
enough).  No heat experienced this morning.  Is there any other type of
arrangement for attachment of the heater cable to the valve that doesn't
allow for the play experienced?  I would hate to bend the wire around
and have the end break off but if there is some type of clip that could
be installed, that would solve the problem.  Anyone have any ideas?

William